Fix typo in abstract query generator

lib/dialects/abstract/query-generator.js

@@ -297,7 +297,7 @@ module.exports = (function() {
       } else if (Utils._.isObject(obj) && 'raw' in obj) {
       } else if (Utils._.isObject(obj) && 'raw' in obj) {
         return obj.raw
         return obj.raw
       } else {
       } else {
-        throw new Error('Unknown structure passed to order / group: ' + JSON.stringify(ojb))
+        throw new Error('Unknown structure passed to order / group: ' + JSON.stringify(obj))
       }
       }
     },
     },